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Preparation method of 4-hydroxy-2,2-dimethyl-1,3-benzodioxole

A technology of dimethyl and dimethoxypropane, which is applied in the field of preparation of 4-hydroxy-2,2-dimethyl-1,3-benzodioxin, can solve problems such as unfavorable industrialized production, and achieves The effect of low material ratio, improved selectivity and high conversion rate

Active Publication Date: 2015-03-25
湖南海利常德农药化工有限公司
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Problems solved by technology

[0005] US2006247283A reports the synthesis of 4-hydroxyl-2,3-dimethyl-1,3-benzodimethanone by using pyrogallic acid (pyrolic acid for short) under the action of methanesulfonic acid acidic catalyst and DMP at a feed ratio of 1:2 Oxol, the yield is 40.3%, and the product requires column chromatography, which is unfavorable for industrialized production

Method used

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  • Preparation method of 4-hydroxy-2,2-dimethyl-1,3-benzodioxole

Examples

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Embodiment 1

[0014] Embodiment 1: Φ 1.5cm, height 120cm and the rectifying tower with condenser are housed on the reactor of 1000ml band agitation, the rectifying tower bottom fills 10cm methanesulfonic acid dry resin catalyst, adds 100.8g in the reactor (0.8mol) pyrogallic acid and 580ml toluene, after stirring and dissolving, the temperature is raised to 110°C, and the mixed solution of 124.8g (1.2mol) 2,2-dimethoxypropane (DMP) and 60ml toluene is started to be added dropwise. Dropwise reaction, control the DMP and toluene drop rate in 6 hours to complete the addition. The by-product methoxypropene (MP) and by-product methanol produced by the reaction pass through the rectification tower, and react under the action of methanesulfonic acid dry resin at the bottom of the rectification tower to generate raw material 2,2-dimethoxypropane (DMP ), the newly generated DMP returns to the reactor to participate in the reaction of preparing 4-hydroxyl-2,2-dimethyl-1,3-benzodioxol again. The exce...

Embodiment 2

[0016] Add 100.8g (0.8mol) pyrogallic acid and 580ml xylene in the 1000ml band stirred reaction kettle of the rectifying tower that Φ 1.5cm, high 120cm, bottom filling 10cm methanesulfonic acid dry resin catalyst are equipped, Raise the temperature to 110°C, start to drop the mixed solution of 124.8g (1.2mol) DMP and 60ml xylene, control the rate of addition to finish adding in 6 hours, the by-product methoxypropene (MP) and by-product methanol produced by the reaction After passing through the rectification tower, the raw material 2,2-dimethoxypropane (DMP) is regenerated under the action of methanesulfonic acid dry resin, the catalyst at the bottom of the rectification tower, and the newly generated DMP returns to the reactor to participate in the preparation of 4-hydroxy -2,2-Dimethyl-1,3-benzodioxol reaction. The excess by-product methanol is removed from the tower top condenser, and the product 4-hydroxy-2,2-dimethyl-1,3-benzodioxol reaction liquid is obtained in the towe...

Embodiment 3

[0018] Equipped with mechanical stirring and tower diameter 1.5cm, tower height 120cm, in the 1000ml reactor that equal diameter 10cm high methanesulfonic acid catalyst is housed at the bottom of the tower, add 100.8g (0.8mol) pyrogallic acid and 580ml toluene, heat up To 125 ℃, start to drop the mixed solution of the DMP of 124.8g (1.2mol) and 60ml xylene, control the rate of addition and add in 6 hours, the by-product methoxypropene (MP) that reaction produces and by-product methyl alcohol pass through The rectification tower, under the action of methanesulfonic acid dry resin, the catalyst at the bottom of the rectification tower, reacts and regenerates the raw material 2,2-dimethoxypropane (DMP), and the newly generated DMP returns to the reactor to participate in the preparation of 4-hydroxy- 2,2-Dimethyl-1,3-benzodioxol reaction. The excess by-product methanol is removed from the tower top condenser, and the product 4-hydroxy-2,2-dimethyl-1,3-benzodioxol reaction liquid ...

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Abstract

The invention discloses a preparation method of 4-hydroxy-2,2-dimethyl-1,3-benzodioxole (called dioxole for short). According to the preparation method, pyrogallic acid and 2,2-dimethoxy propane are taken as raw materials, methyl benzene or dimethyl benzene is taken as a reaction solvent, methanesulfonic acid dry resin is taken as a catalyst, a rectifying catalytic reaction mode is adopted, and the catalyst is arranged at the bottom of a rectifying tower positioned between a reaction kettle and a condenser; by-products methoxyl propylene and methanol which are generated through reaction are reacted under the action of the catalyst when passing through the rectifying tower to generate the raw material 2,2-dimethoxy propane, and the 2,2-dimethoxy propane is returned to the reaction kettle to participate in the reaction for preparing the dioxole again; surplus by-product methanol is transferred from the condenser positioned on the top of the rectifying tower, and a product is obtained from a tower kettle. The preparation method disclosed by the invention is simple in technological operation and high in reaction selectivity, and can be used for promoting the reaction equilibrium to move towards a target product direction, thus achieving the effects of low material consumption, high transformation rate and high selectivity; in addition, reaction liquid obtained through synthesis can be used for synthesis of active compound bendiocarb, no three wastes are basically generated and industrialized production is facilitated.

Description

technical field [0001] The invention relates to a preparation method of 4-hydroxy-2,2-dimethyl-1,3-benzodioxol. Background technique [0002] 4-Hydroxy-2,2-dimethyl-1,3-benzodioxol is an important intermediate of highly efficient, economical and safe carbamate pesticide difenoxacarb. Most of its synthetic methods use pyrogallic acid to react with 2,2-dimethoxypropane. [0003] [0004] US3969416 report takes toluene, xylene as solvent, and pyrogallic acid and 2,2-dimethoxypropane (abbreviated as DMP) react to generate 4-hydroxyl-2,3-dimethyl-1,3-benzodioxine Mao, the yields are 86% and 92% respectively, but the proportion of pyrogallic acid and DMP (2,2-dimethoxypropane) is 1:3, the by-product MP (methoxypropene) and excess DMP, etc. need to be treated, and the production of alkaline wastewater brings great pressure on environmental protection. [0005] US2006247283A reports the synthesis of 4-hydroxyl-2,3-dimethyl-1,3-benzodimethanone by using pyrogallic acid (pyrolic...

Claims

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Application Information

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IPC IPC(8): C07D317/46
CPCC07D317/46
Inventor 徐建兵刘伟陈明王宇黄超群曾敬
Owner 湖南海利常德农药化工有限公司
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